The invention relates in general to slewing bearings and in particular to slewing bearings that can withstand severe loads without separation.
Personnel transport vehicles may be equipped with a rotating turret. Examples of military personnel transport vehicles with rotating turrets include the High Mobility Multipurpose Wheeled Vehicle (HMMWV), the Mine Resistant Ambush Protected (MRAP), and the MRAP All-Terrain Vehicle (M-ATV). The rotating turret may be mounted to the inner race of a large slewing bearing. In some vehicles, the turret may include a gun, such as a .50 caliber machine gun, a sling seat for the gunner, and extra armor mounted on the turret or around the turret to protect the gunner. Because of the weight and size of the extra armor, the slewing bearing may separate during a catastrophic event, such as a vehicle rollover.
Manufacturers have produced large slewing bearings of various designs for cranes, excavators, windmills, and other heavy machinery. Special design considerations exist for stewing bearings for rotating turrets on military vehicles. The slewing bearing on a military vehicle needs to be blast-resistant. Ideally, the slewing bearing must be able to withstand severe loads and support protective armor while being lightweight in construction. The bearing must be able to withstand the transient impulse loads that result from traversing off-road environments. The off-road environments may be traversed at various speeds, and the bearing may experience impact and blast loads.
Yet, the bearing should be as lightweight as possible to minimize the additional weight on the vehicle's suspension. In the past, such slewing bearings have been constructed mostly of aluminum, which may be limited in both strength and stiffness. Because of the size and weight limitations of the slewing bearing in a personnel transport vehicle, the options for handling dynamic thrust loads are limited.